Unloading double check valve



Dec. 10," 1946. E. A. ROCKWELL EI'AL 2,412,428

UNLOADING DOUBLE CHECK VALVE Filed Dec. 24, 194:

Edward (2. Rockwell PatentedDec. 1946 UNLOADING DOUBLE CHECK VALVE 7Edward A. Rockwell, Cleveland, and Jay M. Roth;

Euclid, Ohio, assignors to Pesco Products 00., a corporation of OhioApplication December 24, 1943, Serial No. 515,604

(Cl. 13l153) 3 Claims.

. 1 I The present invention relates to pressure regulating valvearrangements and particularly to arrangements of this type efiective'toreceive a pressure fluid from a constantly operating generator anddeliver the same to and maintain a selected range of pressures in anaccumulating system, unloading or relieving the generator to the lowpressure return when a selected maximum Pressure is obtained.

It is an object of this invention to simplify the construction of anunloading valve assembly such as contemplated herein, and to improve theefficiency and operation thereof;

A more particular object is the provision of a improved control valveassembly including a pressure delivery valve anda relief return valve,the two valves being connected together against relative movement andbeing eilective to alternately engage respective corresponding valveseats and having adjustable resilient means for urging the relief returnvalve in the direction of seating the inlet stub. Inlet stub t isthreaded to receive a coupling 9 for the feed pipe to leading from thepump (not shown), and the relief or unloading stub 8 is threaded toreceive the fluid return pipe II that leads from the housing back to thepump. The outlet stub l' is threaded to receive a flanged coupling l2having a threaded central opening for connection with the pipe l3leading from the housing to an accumulator or like structure (notshown).

The inlet stub 5 is provided with a port II to discharge the fluid intoa neck portion I5 of the housing that is between the outlet stub l andreturn or unloading stub 8. This flow is controlled by a one-way outwardpressure check it also has passages l9 through its cylindrical positionthereof with a force which has a maxiskilled in the art after theconstruction and operation of this double check unloader valve isunderstood from the within description.

It is preferred to accomplish the numerous objects of this invention andto practice the same in substantially the manner hereinafter fullydescribed and as more particularly pointed out in the appended claims,reference being made to the accompanying drawing that forms a part ofthis specification and wherein the single figure is a longitudinalsectional view taken axiallythrough a valve structure incorporating apreferred embodiment of the present invention.

The drawing is .to be understood as being of a, more or less schematiccharacter for the purpose of disclosing typical or preferred forms ofthe 'improvements that are contemplated herein.

Referring in greater detail to the drawing, a hollow housingi ofelongate cylindrical shape is provided with a lateral high pressureinlet stub 6, an axial high pressure outlet stub for the flow of fluidfrom the pump to an accumulator or accumulating system (not shown), anda low pressure return or unloading stub 8 that projects laterally fromthe housing in a direction opposite wall which permit the fluid to flowto the discharge port M when this check valve is unseated.

A coil compression spring 2c is interposed between check valve it andthe wall of the housing that bounds the outlet port 14, and this springurges the check valve in a direction toward tts seat I8.

The pressure of the fiuidfrom the pump will push the valve away from itsseat to effect the passage of the fluid into the housing and anytendency of the fluid toreverse its normal direction of flow will resultin the closure of the valve. The neck portion iii of the housingprovides a guide for the spindle of a double check valve assembly and atends of this neck portion there are valve seats 2land 22 that face inopposite directions away from each other. The spindle 23 is providedadjacent its ends with splines 24 and 25 that guide the spindle inreciprocal sliding movement in the neck, the said splines alsoDermitting the passage of thefiuid in either direc- Mon through saidneck; The spindle terminates adjacent the seats 2| and 22, and at itsends it is provided with check valves 26 and 21 that are alternatelyengageable with the respective seats 2| and/22 to control flow throughthe outlet stub I or the return stub B. These valves 26 and 21 havetheir chamfered portions facing in opposed directions toward each other.The valve 26, whichhas a greater area than that of the valve 21, is

preferably a separate element that is anchored upon a threaded stub 28at the adjacent end of the spindle by a clamp nut 29providing for readyassembly and disassembly. 5

Yieldable means are provided tourge. the reciprocal double check valveassembly in one direction of its movement; to normally seat the checkvalve 21 and open the valve 26. These respectivepositions, which areshown in the drawing, are such that the flowing fluid moves past checkvalve 26 to pass out of the housing through the high pressure outletstub and pipe I3 to the a toggle having elongate arms 30 and 3| ful-.

crumed on a pin 32 mounted in the ears of a yoke 33 that is providedwithdisc-shaped seat 34 and an upstanding post 35. In the arrangement shownthe outer or free end of arm 3|] bears,

against the inner end of a tapered recess 36 in the spindle 23 of thereciprocal check valve assembly, and the free end of arm 3| bearsagainst the inner end of a tapered recess 31 in a threaded conical plug38 that is'screwed into the end of the housing adjacent the reliefreturn stub 8. The recess 36 extends a considerable distance into thespindle 23 so that the end of arm 30 has its bearing located at a pointbetween the respective check valves 26 and,2| and beyond the axis of theinlet check valve. The seating of check valve 21 provides a stop forarresting the downward movement and prevents straightening of the to glethereby preventing the fulcrum 32 reaching a dead center position. v

The fulcrum or knee of the toggle is urged downward, tending tostraighten the arms 30 and 3|, by the action of a coiled tensionspring39 that is interposed between the disc-shaped seat 34 and afollower 40 that is adjustably mounted in a tubular boss 4| n thehousing above the fulcrum 32 of the toggle. The follower 4|] has athreaded edge that engages internal threads in the boss 4| and it has acentral aperture 42 that'is provided with an inwardly projecting lug 43.The means for rotating the follower 40 comprises an elon gated winding.rod 44 that passes through aperture 42 and has a longitudinal groove 45to accommodate the lug 43. A flanged apertured cap 46 screwed upon theupper end of boss 4| provides a mounting for the winding rod 44 andpermits rotation of the rod but also prevents longitudinal movementthereof. The adjustment of spring tension is readily accomplished tocause the follower to be moved up or down in the boss 4 v To furtherinsure the completion of opening movement of relief return valve 21,once the samehas been initiated there maybe provided a piston-likemasking surface 26a on pressuredelivery valve 26 cooperating with acomplementary cylinder masking surface 2|a. When the closing movement ofvalve 26 has been initiated the masking surfaces'2la and 26a are broughtinto cooperative relation thus restricting the flow past valve 26. Thecorresponding opening of relief return valve 21 causes a momentary dropof pressure within the reduced neck portion l of the housing below thatpressure existing on the accumulator side of pressure delivery valve 26with While this invention has been described in detail in its presentpreferred form or embodiment, it will be apparent to persons skilled inthe art, after understanding the improvements, that various changes andmodifications may be made therein without departing from the spirit orscope thereof.

We-claim:

1. In an unloading valve arrangement including a housing having an inletport, a high pressure outlet port, and a low pressure unloading port.valve seats in said housing at opposite sides of said inlet port, adouble check valve assembly the result that the accumulator pressureacts on valve 26 as a piston insuring the movement of the assembly tothe rightin the drawing.

cooperating with said seats comprising a reciprocal spindle, valves onsaid spindle alternately engageable with said seats, one valvecontrolling flow through said low-pressure unloading port and the othervalve controlling flow through said high pressure outlet port, meansdefining a tapered recess extending into said spindle from the back ofthe'low pressure valve and forming a bearing disposed axially betweensaid valves thus improving the balance and stability of operation, atoggle having a first link engaged at one end in said recessed bearingand having a second link engaging a'fixed bearing at its other end, andresilient means exerting pressureagainst said toggletending to extendthe same to seat said one valve and to unseat said other valve.

2. In an unloading valve arrangement including a housing having inlet,outlet, and unloading ports, a one-way outward pressure check valvecontrolling flow through said inlet port, double check valves.connectedto each other for simultaneous operation to effect alternate opening andclosing of said outlet and unloading ports, a toggle engaged at one endwi i said connected double check valves; said toggleacting to normallyopen said outlet valve and to seat Said un-' loading valve, the seatingof said unloading valve providing a stop to limit extendable movement ofthe arms of said toggle in one direction, the

seating of said outlet valve providing a stop to limit the collapsingmovement of the arms of said toggle in the opposite direction, saidoutlet port and said associated valve being provided with cooperatingmasking surfaces effective to improve the positive openingcharacteristics of said unloading valve, and an adjustable tensionspring operating against said toggle to urgethe toggle arms in saidextendable direction of movement.

3. An unloading valve arrangement comprising a housing having inlet,outlet and unloading ports; an outward pressure check valve controllingsaid inlet port; valve seats in said housing at opposite sides of saidinlet port; a double check 1 valve unit arranged for reciprocal movementto alternately engage said seats thereby to control being effective toimprove the positive opening characteristics of said unloading portvalve.

EDWARD A. ROCKWELL. JAY M. ROTH.

